<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <style>
    .blue {
      color: blue !important;
    }
    .static {
      background-color: #ff9dac;
    }

    .text-danger {
      color: red;
    }

    .red-bg {
      background-color: red !important;
    }

    .white-text {
      color: #fff;
      /*background-image: linear-gradient(red, green, blue);*/
    }
  </style>
</head>
<body>
<div id="app">
  <h1
    class="static"
    :class="{ blue: isActive, 'text-danger': hasError }"
  >hello vue -> style</h1>
  <h1
    class="static"
    :class="classList"
  >hello vue -> style</h1>
  <div class="box" :style="{height: calcHeight, background: bg}"></div>
  <button @click="isActive = !isActive">change style</button>
  <ul>
    <li
      v-for="item of 5"
    >{{item}}. item-{{item}}</li>
  </ul>
</div>
<script src="vue.js"></script>
<script>
  const app = new Vue({
    data: {
      activeIndex: 1,
      calcHeight: 120 * 2 + 'px',
      bg: `linear-gradient(red, green, blue)`,
      isActive: true,
      hasError:  true,
      classList: {
        'red-bg': true,
        'white-text': false
      }
    },
  }).$mount('#app')
</script>



</body>
</html>